1. Technical Field
The present invention relates to an antibacterial product and a method of manufacturing the same.
2. Description of the Related Art
Typical food containers, for example, portable containers for water and beverages, such as vacuum bottles and water bottles, are known to have a drawback in that various bacteria or oral bacteria (such as Streptococcus mutans), which arise from contamination of a portion coming into contact with the lips of a user or the saliva of the user, or which are adhered to the fingers, are mixed with the water in the water bottle or are adhered to the water bottle when the user drinks water from the water bottle, thereby allowing various bacteria to proliferate in the water bottle. Further, it has been pointed out that there is a risk of attachment of harmful food-poisoning bacteria such as E. coli, or Streptococcus mutans, to the water bottle, or of allowing putrefactive bacteria to proliferate in the water bottle. Water bottles having an effective function of preventing bacteria from proliferating, or of killing and eliminating bacteria, have not yet been released to date.
The main reason is considered to be that, since a conventional heat-retaining vacuum water bottle mainly contains hot water at high temperatures and the main function of the vacuum water bottle is to minimize the reduction in temperature over time, it is mistakenly believed that various bacteria have difficulty surviving in the hot water contained in the water bottle, and that the sanitation of the water in the water bottle is thus maintained.
However, when the temperature of the water is reduced to a temperature of water that is capable of being drunk by humans, especially a temperature lower than body temperature, bacteria actively proliferate. Recently, beverages including sport drinks are more frequently stored at room temperature or at cold temperatures than at hot temperatures, depending on the season, and thus the contamination of the liquid in containers by bacteria has attracted attention, and symptoms such as diarrhea have occurred.
Particularly, children frequently drink beverages from the same bottle, and thus problems related to the contamination of water by, for example, Streptococcus mutans in the bottle are increasing. Accordingly, there is increased expectation of the development of a water bottle having water purification and water quality maintaining functions.
On one hand, containers for storing meat or fish are useful, and are mostly large-sized and the number thereof is already large. In particular, there are many cases where a considerable amount of meat or fish is stored in water. Further, the case where such food is allowed to stand in the state of being contaminated with food-poisoning bacteria is difficult to recognize or prevent. This problem is regarded as very important in terms of food hygiene, like the water-related problem of the bottle.
On the other hand, a plastic plate, when used as a kitchen board, which is a food preparation tool useful in the kitchen of every household and is usually used to cut food to be cooked, is problematic in terms of maintaining the hygiene thereof because E. coli and the like may be adhered to the surface thereof. With the goal of solving this problem, an antibacterial kitchen board realized by adding a plastic material with an antibacterial agent is currently sold, but desired antibacterial performance may be difficult to realize merely by the simple addition of an antibacterial agent.
Even when such an antibacterial agent is added, particles thereof are physically distributed in the plastic after the molding process, and most of the particles are not exposed to the surface of the plastic. This is considered to be due to a physical phenomenon in which a molten plastic, having low resistance, occupies the mold contact surface upon moving while coming into contact with the surface of the mold. Hence, non-plastic particles are confined inside the molten plastic, thus making it substantially impossible to expose heterogeneous molecules contained in the plastic to the surface of the plastic under the same mass condition between the plastic and the antibacterial agent, which was proven through the antibacterial testing of Examples of the present invention.
A typical antibacterial ability test requires that an antibacterial effect be achieved within a reference time of 24 or 48 hr. However, in practice, a user is considered to expect an antibacterial effect by which harmful bacteria in a food container, including a water bottle and a vacuum bottle, are killed within at most 6 hr, preferably 3 hr, and more preferably 2 hr.
Harmful bacteria start to proliferate when they are accidentally mixed with beverages in the water bottle or the vacuum bottle, but at the same time harmful bacteria need to be prevented from proliferating, that is, they need to be killed. Furthermore, in consideration of the period ranging from the time at which the container is filled with a beverage to the initiation of drinking or to the completion of drinking, a reference time of 24 hr is very long from the standpoint of common sense, and the water in the water bottle is expected to have already been drunk within 24 hr.
Therefore, from the standpoint of common sense, the antibacterial ability needs to be confirmed in an antibacterial test in which antibacterial ability sufficient to completely kill harmful bacteria or to secure a viable cell count of 100 cells/cc or less within at most 6 hr, preferably 3 hr, and more preferably 2 hr after filling the container with water, is realized in a short time. The antibacterial function of silver has been known for a long period of time to be realized by silver oligodynamic action, activating dissolved oxygen in water that is in contact with the silver surface. The history of using silver, having this main characteristic, in dishes or to store beverages is long, and the antibacterial and bacteria-reducing functions of silver are considered to be obtained not by so-called chemicals but through active oxidation. Needless to say, silver is not at all harmful to humans, and does not affect bacteria that are beneficial to humans, for example, Lactobacillus, but has strong antibacterial and sterilizing effects on food-poisoning bacteria and anaerobic bacteria, which are harmful to humans, due to active oxidation of the surface thereof, and the silver oligodynamic action is known to have safe antibacterial and sterilizing effects.
Meanwhile, Korean Registered Utility Model No. 20-0377167 discloses an antibacterial silver container that resists discoloration. However, the aforementioned Korean Registered Utility Model describes only an antibacterial effect obtained after 24 hr by using nano-sized pure silver powder as a component having an antibacterial function.
In the present invention, various tests have been made in order to realize a sterilizing ability in a short time. The use of pure silver resulted in poor sterilizing ability in a short time. However, products made of silver sintered under a nitrogen atmosphere or silver oxide sintered under an oxygen atmosphere have been proven to achieve 100% sterilization within at most 6 hr, preferably 3 hr, and more preferably 2 hr.